From the onset of civilization there has been a compelling need to determine the truthfulness of individuals when transgressions have occurred. In the first recorded criminal investigation, a homicide was committed and when questioned, the suspect answered the relevant question with a question: “Am I my brother’s keeper?” Of course, God knew that Cain was guilty and He pronounced Cain’s sentence. Further instructions were set in place to help determine truth from lies and God commanded that no person could be found guilty except on the word of two or more witnesses. This was all done in an effort to establish justice - let the guilty be punished and the innocent be set free.

Over the centuries there have been many efforts to refine the rule of ‘two or more witnesses’ with additional methods of truth verification. An example of this would be circa 500 B.C. in India. A priest put lampblack on the tail of a donkey in a dark room and all suspects were to pull the magic donkey’s tail. They were told that when the one who was the thief pulled the magic donkey’s tail, he would speak and be heard throughout the temple. The person who did not pull the tail had clean hands and was pronounced the thief and punished.

The first recorded effort to construct a mechanical device to measure emotion and determine truth and deception came from Cesar Lombroso. In 1885 Lombroso was recording changes in blood pressure in police cases in Italy with some success.

The next innovation in lie detection came in 1914 when Vittorio Benussi measured breathing to determine truthfulness.

At about the same time an American, William Marston, also utilized blood pressure changes in truth verification and attempted to use a crude GSR while examining German POW’s. Marston was not impressed with the GSR and discontinued its use.

In 1920 John Larson, a Berkeley (CA) police officer, was the first to record at one time for the purpose of lie detection both breathing and blood pressure. He named his instrument the Polygraph (many writings). In 1923, the results of a polygraph test were admitted as evidence into a criminal proceeding. When the case was appealed (U.S. v. Frye), the Supreme Court ruled that polygraph evidence was not reliable enough to be allowed into court as evidence. Seventy-five years later, in 1998, the Supreme Court, after hearing all of the scientific validity studies concerning the polygraph, again ruled in U.S. v. Scheffer that “There is no consensus in the scientific community that polygraph evidence is reliable.” in upholding the government’s ban on the introduction of polygraph evidence into court. The Court went on to encourage states to never allow polygraph evidence into court proceedings. Lawyers for the U.S. Department of Justice argued that polygraph evidence is unreliable and that it is not difficult to defeat the examinations.

In the 1930's, Leonard Keeler incorporated the GSR into his polygraph and started the first polygraph school in 1948.

Although there were a number of minor changes to the polygraph from the Keeler Polygraph in 1948 to the advent of the computerized polygraph in 1994, the basic machine and its functions remained the same. The advent of the computerized polygraph had very little effect on either the accuracy of the system or the number of law enforcement agencies that relied on it.

In 1971, Olof Lippold, a researcher at University College London, published the results of research that he had begun in 1957 in the magazine ‘Scientific American’. Lippold’s article, entitled ‘Physiological Tremor’, explored the initial discovery by Martin Halliday and Joe Redfearn of the physiological tremor a decade previously at the National Hospital in London. Halliday and Redfearn had discovered that the contraction of a voluntary muscle is accompanied by tremors of the muscle in the form of minute oscillations. They further found that the major part of the physiological tremor consisted of an oscillation of the reflex mechanism that controls the length and tension of a stretched muscle, and has a frequency between 8 and 12 Hertz. Lippold explained that the tremor is believed to be a function of the signals to and from motor neurons and that it is analogous to the self-adjusting, closed-loop servosystem.

In 1970, and prior to the publishing of Lippold’s article in 1971, three military officers retired from the U.S. Army and formed a company which they named Dektor Counterintelligence and Security. The three officers were Alan Bell, Bill Ford and Charles McQuiston. Bell’s expertise was in counterintelligence, Ford’s was in electronics, and McQuiston’s was in polygraphy. Ford had invented an electronic device that utilized the theory of Lippold, Halliday and Redfearn in which he tape-recorded the human voice, slowed it down three to four times its normal rate, and fed it through several lowpass filters which then fed the signal into an EKG strip chart recorder. The strip chart recorder then made chart tracings on heat sensitive paper. They named their device the Psychological Stress Evaluator (PSE 1). Although Dektor CI/S was intended to be a security company, the PSE immediately became a success and their focus became centered on this system. One of the first individuals hired by Dektor was a polygraph examiner with a local police department which had started utilizing the PSE. This individual, along with McQuiston, wrote a three-day training course based on their polygraph experience and utilizing polygraph formats.

From 1971 until 1975, the PSE prospered as there was much discontent with the traditional polygraph and many in both private industry and law enforcement were looking for an alternative. However, the well-entrenched polygraph community, represented by the American Polygraph Association, saw voice stress analysis as a threat to its existence and began an intense campaign to stop its spread. A ‘Uniform Polygraph Law’ to license polygraph examiners was drafted by the APA and sent to each of its state association members to be introduced into their respective Legislatures. Although it was submitted into all 50 State Legislatures, only 13 passed it into law. This may have been due to the fact that hidden in the law to license polygraph examiners was a clause that gave a strict definition of the instrument to be used for all lie detection. This clause defined the three functions of the polygraph machine. It further stated that any person who purported to be able to detect deception must use this instrument, take polygraph training and obtain a polygraph license. Unknowingly, legislator’s in 13 states had outlawed voice stress analyzers or any future device as lie detectors.

1975 was the year that the International Society of Stress Analysts was formed by a medical doctor and a Ph.D. They had recently purchased their own PSE and formed their own company which they named Diogenes. They then announced that they were starting their own training school for voice stress analysis. Because of the dissatisfaction with Dektor’s three-day school, a number of other schools were also started by individuals around the country. Voice stress analysis soon began to suffer the same difficulties as polygraph in that most of the schools were being run by novices. Each sought to outdo the other by developing ‘new and improved theories’ to attract students which they taught along with the theories taught by Dektor. This led to very serious errors and gave the polygraph community more ammunition in decrying voice stress analysis as ‘voodoo in a box’. The faulty theories taught by these schools that were the most damaging to the success of voice stress analysis were: the Outside Issue question, the Guilt Complex Reaction question, utilizing colors as controls, and running back-to-back relevant questions.

It was about this same time that others in the private sector recognized that there was a very attractive market for the voice stress analyzer and although they were unable to use the technology of the PSE because it was patented, they ‘invented’ their own vsa’s and soon were competing with Dektor. These units, CCS’s Mark 1, LEA’s Mark V, Verimetrics, and the Hagoth offered little or no training and their inaccuracies soon began to do great damage to a discipline still in its infancy. These ineffective vsa’s, along with the poor training offered by Dektor and the number of inept training schools, along with the assaults by a very well-organized and well-funded polygraph industry had driven voice stress analysis into near oblivion by 1982. They also caused Dektor to seek Chapter 11 bankruptcy protection in 1982. For all intents and purposes, voice stress analysis was dead.

In 1986 a nationally-recognized company made the decision to produce a new voice stress analyzer utilizing the latest in technology. In searching for an individual with the expertise to head up the project, they chose Charles Humble, a voice stress and polygraph examiner from Indianapolis, IN, who had not only built a successful lie detection business, but who had also discovered ‘delayed stress reaction’ while forming his own training school for voice stress analysis in 1981. Humble published his findings and restructured test formats accordingly, dramatically changing the face of voice stress analysis by greatly increasing its accuracy rate (50% of all deceptive reactions displayed in the pattern of the following question). Humble also developed an interviewing technique which he called Defense Barrier Removal (DBR). DBR incorporated the kinesic interviewing techniques and greatly increased the interviewer’s ability to identify guilty subjects and to then elicit confessions from them. The combination of an accurate system, validated formats and proven testing protocols, as well as a dynamic training program was the formula for the future success of voice stress analysis in the law enforcement community.

In 1988 the Computer Voice Stress Analyzer™ was debuted by the National Institute for Truth Verification to a market that had less than fond memories of voice stress analysis. Although it was initially difficult to convince law enforcement to take the CVSA™ seriously, many in the Midwest law enforcement community were so convinced by their previous experience with Humble that they gave it a try. Very slowly word spread throughout law enforcement that the CVSA®, along with the outstanding training at the NITV, was replacing the polygraph in every agency which purchased it. Because the NITV did not advertise and relied solely on word-of-mouth for its sales, the polygraph community, disorganized by the almost total elimination of private sector polygraphists, was unaware of the steady growth of voice stress analysis. Most polygraph examiners were under the impression that voice stress analysis had been eliminated as competition; however, by 1995, use of the Computer Voice Stress Analyzer had grown so widespread in law enforcement that organizations such as the Florida Polygraph Association, the Wisconsin Polygraph Association, and the California Polygraph Association launched smear and disinformation campaigns against the CVSA® and the NITV®.

They were aided by the Department of Defense Polygraph Institute which conducted parlor games with the CVSA® and issued a ‘Position Statement’ in which they declared that they found the CVSA® to be unreliable as a truth verification device. This ‘Position Statement’ was then disseminated to each State Polygraph Association which, in turn, gave a copy to each member for further dissemination to their respective agencies. However, Victor Cestaro, a physiologist and researcher at the DoD Polygraph Institute, issued a paper entitled ‘A Comparison Between Decision Accuracy Rates Obtained Using the Polygraph Instrument and the Computer Voice Stress Analyzer® (CVSA®) in the Absence of Jeopardy’ in which he stated that “The lab simulations established that the CVSA® performs electrically according to the manufacturer’s theory of operation.....These data indicate that there may be a systematic and predictable relationship between voice patterns and stress related to deception.”

1988 was also the year that congress passed the 1988 Employee Polygraph Protection Act. This law prohibited private employers from administering polygraph examinations to employees and was passed due to the tremendous outcry from the public over the inaccuracies and abuses of the polygraph in the private sector for many years.

Soon after introducing the CVSA® into the market, it became clear that the system could easily be utilized by those in organized crime to identify undercover law enforcement agents. Foregoing the obvious profits of sales in this area, the NITV withdrew the CVSA® from the private sector in 1991 and restricted the sale of the CVSA® to qualified law enforcement agencies.

The original Computer Voice Stress Analyzer® underwent a number of upgrades over the years to make it more user-friendly and in 1997, the NITV® unveiled the digital notebook version of the Computer Voice Stress Analyzer® to rave reviews. Engineers for the NITV® are now working to develop an algorithm which will quantify chart patterns and assist the examiner with a ‘Cold Call’.

The CVSA®II is now the truth verification device of choice in the law enforcement community as the number of Law Enforcement agencies utilizing the CVSA® continue to grow dramatically, proving the viability of the system for twenty-first century crime detection.

CVSA® Continues to Grow

The CVSA®II is now the truth
verification device of choice in the law enforcement community
as the number of Law Enforcement agencies utilizing the CVSA®
continue to grow dramatically, proving the viability of the
system for twenty-first century crime detection.